Multiplex-simplex extended channel system



April 30, 1940. K. B. DUERR MULTIPLEX-SIMPLEX EXTENDED CHANNEL SYSTEM 2Sheets-Sheet 1 no U,

V- IIIIL ATTORNEY MULTIPLEX-S'IMPLEX EXTENDED CHANNEL SYSTEM Filed July24, 1937 2 Sheets-Sheet 2 lINVENTOR K. B. DUER R FIG. 3

SYM.

ATTORNEY Patented pr. 30, `1940 Y I t i i UNITED STATES lol-FicsMULTIPLExrslMPLEX EXTENDED CHANNEL SYSTEM A Karl B. Duerr, Fairlawn,J.-, `assiigrncry-to The Western Union Telegraph Company, New York, N.Y., a corporation of 4New York Y i Application July 24, 1937, Serin No.155,419

oola'ims. (o1. 11s-f2) This invention relatesv primarily to multiplexthe first ymethod had the disadvantage of poor extended channel systemsand more particularly economy while the second method did not make tomeans whereby one/or more channels ofamultias eicient use of circuitsbetwen 'main offices as plex circuit extending to or continuing Afrom awould bef-possible ifvsuch circuits employed a 5- start-stop orsimplexfoperated telegraph system channelY of -afmultiplex "5 may befurther extended to or continued from .It is therefore one of the mainobjects of this one or more other channels of another multiplexinvention to provide a Ineans Whereby predetercircuit extending to or'continuing from other mined Sections of a Way Wire circuit may be01ostart-stopor simplex operated telegraph systems. erated inconjunction With vmultiplex equipment Oftentimes in telegraph practiseit is very deand other sections of the circuit may be operated 10Vsirable to be able to interconnect a plurality of in conjunction withsimplex equipmenttelegraph branch offices or subscribers stations, lkMore specioally, it is an object'of this invenhereinafter considered tobe the equivalent of ay *l tiontoxprol/'ide a multiplex eXtended channelsysbranch oiilce, in series with one another or by temWithsimpleX'operated drop" facilitiesfat what is known in the art asbeing connected in a Various points throughout the multiplex channel. 15p way wire circuit, As is well known, in a, Way These and various otherobjects'and advanwire circuit thestations or branch offices vassotagesofthe inVention Will be apparent vas the deciated therewith areconnected in series'and each tailed description of theI inventionproceeds, takbranch oice is able to communicate with each en inconjunction With theaccompanying drawof the others, the signalstransmitted fromV any ings in Whicht one of the branch oces beingreceivedyatr every Figl schematically illustrates the arrangeone of theothers, Because the v01ume0f busiment and main-circuits for three'brancholiices ness from or to a branch ofce is somewhat limand three mainofliees connected and operatingfin ited and is usually not sufficient towarrant the accordance With the invention;

establishment of a direct multiplex circuit, vthe y '-Fig 2 is a diagramillustrating the circuit ar- 2:5;

branch omnes are .usuauy connected with assorangement of thereceiving-section of a repeater ciated central or main offices bystart-stop or located at one ofthe main offices; andi simplex operatedequipment. The branch oflces Fig- 3 is a diagram illustrating thecircuit ardesired to be connected in a, .Way Wire'circui1; rangement ofthe sendingsection of a repeater 1oare likely to be associatedwithdifferent central Lcated at one of the main oces. I A

offices, such as for example, where a single subl Referring rst to Figl, the operation of theV scriber may have a plurality of remotelydisinvention will hereinafter be described as em-k posed plants and/orofces and desire that each bodying three branch offices 0r SubscribersStabe able to communicate directly with each of the tions A, B and C,associated With three diierent others and have all the communicationsrecorded main or central offices X, Y and Z respectiVely 35i at eachstation. Where the branch oices desired It should be kept in mind,hoWeVer, and Will be to be'connected in a way wire circuit are assomoreapparent as the description proceeds, that ciatedL with only two'mainomces, it vis entirely the invention is not by any meanslimited to thefeasbleand practical to connect all `the branch interconnecting of but'threebranch and three by a, simplex operated circuit and directlyConnect creased, the dSCrptOI1 Of the OpelalOIl 0f three the two simplexoperated circuits, one with the being thought sumoient to properl7disclose` the other, by extending or continuing a channel of ainVention- The only limiting factor as t0 the multiplex circuitextendingbetween the two main number of branch ,offices capable of beinginteroffices associated with each main oice in series main oices, as thenumber could 'be greatly in-` 46'? offices. The channel of a multiplexcircuit may connected in accordance with this invention and 45' well beemployed between the main omces, since still function properly isdetermined4 by the Volonly n, part of the line time 0f a circuit is re-`ume of businesslikelyto be handled between the quired, whereas ifY themain offices were constations. The branch Offices Aand .C are shownnected by a Simp1ex operated circuit, the whole for the purpose ofillustration connected to their line time of the circuit Wouldl beoccupied. Where associated main ollces X and Zf respeCtiVely, `by '50 itwas desired to connect branch offices associated simplex operated tielines il and l2, respectively. with more than two main oices,retransmission The hranch'ofiice B is Shown connected to its asof themessages at one or more of the main oices sociated main oiice Y by aloop circuit comprising was required or a simplex circuit had to beemthe two simplex operated 'circuits' I3 and I4.

ployed throughout the .whole circuit.' Obviously, Main omce Y isshownconnected to the main 55 offices X and Z by channels of multiplexcircuits te and I1, respectively. As the signals transmitted from and tothe branch oiices A, B and C are of the start-stop or simplex varietyand the signals transmitted between the main offices are of themultiplex variety, it is necessary to employ means for converting eachtype of signals to the other. To accomplish this, what is known in theart as multiplex-simplex channel repeaters are employed, designated inFig. 1 as MX--PX REPT. One repeater I3 is employed at main oice X, tworepeaters I9 and 2| are provided at main ofce Y and one repeater 22 isused'at main oce Z. The necessity of employing two rpeaters at mainoiice Y will be apparenthereinafter. These repeaters, althoughv somewhatsimilar in operation and function to others such as those disclosed in apatent toNoxon No. 2,014,908, dated September 17, 1935, have certain newand distinct features which will be apparent in the followingdescription thereof. 'I he detailed operation of one'o'f'theserepeaters, such as the one i8 at main office X'will now be given. Theother repeaters |9,'2| and 22"operate in exactly the same manner as theone to be described, with the exceptions hereinafter pointed out.

Referring now to Fig. 2*,which shows primarily the receiving,V part ofthe repeater at main oice X, the multiplex linev I6 is connected to aline relay 23, which is shown duplexed. The marking and spacing contactsof the line relay 23 are connected respectively to negative and topositive battery, and the tongue 24 of the relay is connected byalconductor 26 to the solid ring 21 of areceiving multiplex distributor,indicated in general at 28.

The multiplex distributor 28v may provide for any desired number ofchannels, usually three or four. Onel channel, only is shown complete,which for convenience may be termed the A channel, this being consideredas the channel utilized for messages to be extendedv directly to thebranch office A, or to be received therefrom. The other channels of themultiplex may be operated in connectionV with regular multiplexequipment or with other extended channel equipment, as desired.

Ilhe segmented receiving ring 2 9Vof the distributor 28 has the'segmentsthereof arranged in groups of ve each, the number of groups depending onthe number of channels inthe multiplex circuit andvbeing equal thereto.Only the complete group of segments of the A channel are shown and thefirst four of these segments are connected individually to one terminalof. the windings ofthe rst four relays Sla to 3|d of a series of vepolarized relays Sia to 31e. The fifth segment ofthe A channel isconnected to the break contact of an overlap relay 32. The

kmake contact of therelay 32 is connected by a conductor 33 to aterminal of thewinding of the polarized relay 3|e. The tongue of theoverlap relay 32 is connected through a condenser 34 to a conductor36.The conductor 36 connects the v.opposite terminals of. the windings ofthe relays 3|a to 3|e and one side of the condenser to a tongue 31 of amanually operable switch, indicated in general by reference numeral 38.The

tongues of the switch 38 will be considered to be in contact with theirupper stops and therefore the circuit from conductor 35 continuesthrough i 43, through the upper stop and tongue 44 of switch 38 toground.

The spacing contacts S of each of the polar relays 3m to 3|e areconnected by a conductor 46 through the tongue 41 and upper stop ofswitch 38, over a conductor 48 and thence to the middle left handcontact of a reversing switch 49. The handle of the reversing switch 49is normally closed on its upper contacts and therefore the spacingcontacts of the relays 3| a to Sie are normally connected to ground atthe switch 49. The marking contacts M of the relays Sia. to Sie areconnected, over a conductor 5|, through the tongue 52 and upper stop ofswitch 38, over conductors 53 and 54, through the upper stop and tongue5t' of a manualy operable switch, indicated in general by referencenumeral 51, the tongues of which are normally engaged with their upperstops, thence over a conductor 58, through a jack 59, over a conductor 6i, through the winding of a relay t3, and thence to a branch cnice tieline, such .as the tie line l o f branch oice A. The relay 63 isnormally in its operated condition, as hereinafter described, andtherefore maintains a possible shunt circuit, comprising the tongue 62of the relay and a normally closed key 64, in an open condition. Wherethe branch oice, such as A, Fig. l, is at the end of the way Wirecircuit and is the only branch ofce associated the main ofce, the tieline such as 1 usually extends through the simplex printer thereat andto the ground, l The arrangement of the tie line at a branch ofce suchas B will be hereinafter pointed out.

The tongues of the relays 3 La to 3 le, Fig. 2, are connected byindividual conductors, such as 66, to segments numbered 1 to 5 of asegmented ring 61 of a start-stop distributor of the type well known inthe art and indicated in general by reference numeral Q3. The segmentedring 61 is` also provided with a rest segment R and a start segment Si.A solid ring 6 9 is associated with the segmented ring 1 and both areadapted to be traversed by a4 brush 1|. The start-stop distributor B8has'l two other ringsA 12 and 13 traversed by a brush 14. Both brushes1| and- 14v are adapted to rotate together and are normally held at restby meansrof a latch 16, with the brush 1| on the rest segment R. Thering 12 has a dead or open segment 11 corresponding to the start segmentS of. ring` 61. Therest of the ring 12 is connected to positivepotential and the cooperating ring 134 is connected by a conductorv 18through a winding: 19 of the relay 42 and thence to the tongue 3|thereon The multiplex receiving distributor has in acldition to theheretofore mentioned receivingrings 21 and 29, twolocal rings 82 and 83,the former of which is connected to positive potential. The

ring, 83 has a segment 84 which is connected by a conductor tthrough thecoil of the overlap relay 32, over a conductor 81, through the windingsof the start-stop distributor start magnet 88 and thence over aconductorA 89to the tongue of the cut-off relay 42. The local rings` 82and 8 3 and the receiving rings 21 and 29 are traversed by brushesV 9|and 92, respectively, rotating together.` The brushes 9|,and 92 rotatecontinuously and are kept insynchronism with incoming line signals bymeanswell known in the art.

When the A channel .of the multiplex is idle or no permutation signalsare being.l received thereover, spacing batteryonlyis received over thischannel which, in this. case, holds the4 tongue 24 of thedlne relay 23on,.its. positiveor. spacing contact. Therefore, during such conditionsvas the brush'4 92 traverses segments 1 to 5 of. the ringv 29,associated with the A channeLlspacing battery is applied through theWinding of the v relays 3|a to 3|d and over the circuithereinbefore'described through the winding 4l of the cuto1relay42 toground. Spacing battery flowing from left to right through the operatingv Winding 4|` of the relay 42 holds; the tongue 8| thereof to the left.As described, the Winding of therelay 31e is not connected directly tothe fifth segment of `ring 29 and the manner in which the fifth impulseof a code group is transferred from the iifth segment to relay l3|e`will now be described. As the brushv 92 contacts the fth segment of thering 29, the condenser 34 is charged with a polarity corresponding tothe polarity of n the ring 21 vat this time. When the overlap relay 32is energized by means hereinafter described,

: the tongue thereof makes contact with its make-v ing both spacing andmarking impulses. When spacing impulses are received over conductor 39vatjthey Winding 4| of the cut-off relay 42, the 35lt`o'ngue 8| remainson its left hand linsulated lspacing contact. Therefore, when the brush9| subsequently contacts the segment 84 of the local ring 83, theover-lap relay 32 and the startlma'g-v net 88 Will not be energized asthe circuits there- 406 to are open at the tongue 8| of the cut-01Trelay.

When a marking impulseis received on the solid ring 21, as one of theimpulses of a code group,"

it is'continued bythe brush 92, 4as described,

through the Winding 4l of the cut-off relay 42.

-'I'his impulse being negative causes the tongue 8| to move to itsmarking or right hand contact. Thereupon a locking circuit isEestablished from positive battery at the local ring 12 of the startstopdistributor 58, through -brush 14 'and ring 50313, over conductor 13,throughv the coil 19 of the relay 42 and thence through the tongue 8| Ithereof to ground, and as this locking circuit is more effective thanany subsequent spacing impulses that may happen to be-received on the553- Winding 4| from the ring 2 9 of the multiplex, the tongue willremain for the time being on its marking contact. I i 9| contactssegment 84, a circuit will be completed through the over-lap relay 32and start;

vmagnet 88 to ground, causing them to be energized. The over-lap relay32 being energized causes the relay 3 le to be operated in accordance`with its respective signal impulse and the energization ofthe startmagnet 88 causes the release; `iti-.fof the brushes 1| and 14 of thestart-stop distributor 68. If only the fth impulse of a code,

group happened to` be marking,` the charge of the con-denser would besufficient to cause the winding 4| of the yrelay 42 to operate thetongue 70'38I thereof toits marking contact Which'renders the startmagnet 88 and over-lap relayl 32 operative as heretofore described.

When the brushv 1| of the start-stopv distributor is on the rest segmentR of the ring B1, a rest 751impulse is transmitted-over the associatedbranch Now when the local brush' officeN .tie line such as |I. As ingeneral practice for' start-stop--equipment this rest impulse is aclosed line condition or one during which current isz4 transmitted.'I'he circuit for this rest impulse is from negative potential-at thereversing 5? switch 49 over a conductor 93, through the windingofaneutral relay 94,"Fg. 3, over a conductor 96,Fig, 2,*throughtheupperstop and tongue 91 of sv'vitch 51, over a'conductor 98, through thesolid vring 69,`over the brush 1l, the i'est seg- 10V ment R, aconductor 99,'and conductors 53 and l 54, Vthrough Vthe vupper stop andtongue 56 of. switch 51 and thence by conductor 58, jack 59,conductor'rl, through vrelay 63v and tie line Il to branchoice Agxwherethe circuit is grounded. 151 When 4the brush `1| passes off lthe restsegment R and is contacting 'the start segment S, a start 1 impulse-istransmitted. `AThe start impulse is an interval during Which n0l`Current is being transmittedor an open line condition and While the 20g brush is on the start lsegment S, it will be noted from a` study ofthecircuits that the line circuit will be open at this time, the closed.line circuit heretofore described/being opened at the start segment S;Asthe brush 1|-,successively con- 25 tactssegments numbered l to 5 ofthe ring 61,

the tongues of the relay 3 la.V to 3 |e are successively connected to`battery on the solid ring 69. It will be remembered that the spacingcontacts S o'f'the relays3|a to 3|e are connected to ground 30A at thereversing switch l49 and the marking con-l tacts `M are connected to thetongue 52 of switch 38 which in turnjby'means of its upper stop eX-ltends tothe line Inl.4 Therefore, impulses of current orno current willbe-transmitted to the line 35l Il, depending on'the position of thetongues of kthe relays 3|a tol3le,l as thebrush 1| contacts segmentsnumbered 1 to 5 of ring 61. It will be noted that during the Wholerevolution of the brush 1|' ja steadycurrentis maintained through 40:the'linerelayl94,1Fig.^3, and therefore it will be f held onjits .,1`ghto`r marking side.

IWhile the brush 1| fs on the start segment S, the, brush 14 is onthejdead segment 11 ofy ring 12. Therefore, during this'time the lockingcir- 45 cuitV through the Winding 19 of the cut-off relay 4'2yis openedwhich allows a small biasing current ,flowing through a Winding |0|ofthe cutoffyrelay 42 to move the tongue 8| thereof to the left ontoyits insulated contact. The tongue 8| 50 will remain torrits left contactuntil moved to its right contact by` a `marking impulseA ovving throughthe Winding 4| in response to a marking impulseireceived over themultiplex channel, as hereinbefore described. 55

,",Is'lfie start-stop distributor brushes 1| and 14 rotate 'at'a'slightly higher speedA of rotation than vthe vmultiplex distributorbrushes v9| and 92,' and therefore are brought to rest after eachrevolution thereof ready to be released in conjunction `With the impulsefrom the local segment 84 ofthe multiplex distributor asprevious'lydescribed. a

-Thus the multiplex signals received over a multiplex channel, such asI6, are converted into signalspfthe start-stop variety and are -transvmittedfgo'vena tie line, such vas ll, to the branch oflic'statin' A.Each of the other multiplexsimplexY repeaters operate `in substantiallythe same manner to repeat vsignals kto their Yassociated branchloice.

",I'he transmission iof signals from one of the braricligoilicestations, such "as branch' oilice A, g willnow be described. To transmitthe signals from a branch ofce, which'silnals are of the 75I start-stopvariety, over a multiplex channel, the start-stop signals must beconverted into multiplex signals. This is accomplished by the sendingpart of a multiplex-simplex repeater and comprises in general thereceiving face plate of a start-stop distributor, two relay storingbanks, a multiplex sending ring and a plurality of control and transferrelays. As Well understood, transmitting by means of start-stopequipment consists primarily of opening and closing the line circuit ina predetermined timed relationship for each character signaltransmitted. In the arrangement, such as at branch oiice A, the linecircuit is grounded at the branch oiiice and has potential appliedthereto at the associated main oice, and referring to Figs. 2 and 3,when no signals are being transmitted to or from the branch cnice, theabove mentioned circuit is from ground at the branch oice, through thesimplek receiving-transmitting machine |02 thereat, over the line |I,through the winding of relay S3, conductor 6|, jack 59, conductor 58,the tongue 56 and upper stop of switch 51, conductors 54, 53 and 39, therest segment R of ring 61, the brush 1| and the solid ring 69, conductor98, the tongue 01 and upper stop of switch 51, conductor 96, through thewinding of the line relay 94 and thence over conductor 93 to batteryv atthe reversing switch 40. This circuit holds the tongue |03 of the linerelay 94 on its right hand or marking contact and when a signal istransmitted from a branch ofce the start impulse, which is an open linecondition, allows the tongue of the relay S4 to move to its left hand orspacing Contact. The spacing andy marking contacts of the line relay 94are connected to positive and negative potential respectively. Thetongue |03 is connected by a conductor |04 to the solid ring |06 of thereceiving face plate of the start-stop distributor. Associated with thesolid ring ite is a segmented ring |01 compricing a rest segment R andfive segments numbered 1 to 5 separated by dead segments. A brush |63normally at rest on the rest segment successivelyr bridges the segmentswith the solid ring |56 as it rotates and is normally held in its restposition by a latch |09 adapted to be operated by a start magnet |II.The rest segment R is connected by a conductor I I2 through the windingof the start magnet over a conductor I3, through the winding of aso-called receiving sixth pulse relay iid and thence by a conductor ||6to the marking contact of the line relay 94. The rst and second of thenumbered segments, l and 2 of the ring |01, areconnected by individualconductors ||1 to the tongues ||8 and |I9, respectively, of adiiferentially wound receiving transfer relay |2|, hereinafter referredto as the first receiving transfer relay. The third, fourth and fifthnumbered segments of the ring |01 are connected by individual conductors|22 to the tongues |23, |24 and I 26 respectively by a differentiallywound receiving transfer relay |21, hereinafter referred to as thesecond receiving transfer relay. The break contacts associated with thetongues IIS, IIS, |23, |24 and |26 of relays |2| and |21 are connected by individual conductors |28 to respective individual windings |29 of vafirst relay bank, indicated in general by `reference numeral 3|, and themake contacts are connected by individual conductors |32 to respectiveindividual windings |334 of a second relay bank, indicated in general byreference numeral i3d. The other ends of the windings |23 and |33 are.grounded. A

Individually associated with each of the coils |23 of the relay bank |3|and adapted to be operated in accordance with the polarity of thecurrent iiowing therethrough are a set of five tongues |36. The firstand vsecond of these tongues |36, from the top, are connected byindividual conductors |31 to the break contacts associated with thetongues |38 and |39 respectively of a diiferentially wound sendingtransfer relay I4|. The third, fourth and fifth of the tongues |36 areconnected by individual conductors |42 to the break contacts associatedwith the tongues |43, |44 and |45 respectively of a seconddiiferentially wound sending transfer relay |41. The sending transferrelays I4| and |41 will be hereinafter referred to as the first andsecond sending transfer relays respectively. A set of five tongues |43individually associated with the coils |33 of the second relay bank |34are connected by individual conductors |49 to the make contactsassociated with the tongues |38, |33, |43, IM and Mt of the first andsecond sending transfer relays I4| and |41, the tongues |38, |39, N53,|1115 and |46 being connected by individual conductors II to segmentsnumbered i to 5 of the segmented multiplex sending ring I 52. Associatedwith the segmented ring |52 is the solid multiplex sending ring |53 andthe segments are successively bridged to the solid ring by L"tb-rush|54, continuously traversing the rings. The solid ring is connected by aconductor |56 to the apex of the line relay 23. Thus, as the brush |54contacts the segments l to 5 of the ringl |52, impulses corresponding tothe potential on these segments atA the time of contact will betransmitted to a channel of the multiplex circuit, such as I6.

The detailed operation of the manner in which a character signal istransmitted from a simplex printer to a multiplex channel will now bedescribed. Assume that the two receiving transfer relays |2I and |21 are.deenergized as shown and that the start impulse preceding a. codecombination to be transmitted from branch oiice A causes, by the circuithereinbefcre described, the tongue |03 of the line relay t to move toits spacing contact. This effects the energizationof the start magnetand the receiving sixth pulse relay H4. The following variable impulsesof this code combination, comprising open and closed line conditions,cause the line relay 04 to operate in accordance therewith which in turnapplies positive and negative potential to the solid ring |06, positivepotential being applied for open line conditions and negative potentialfor closed line conditions. The energization of the start magnet |Icauses the release of the brush I QS which rotates in synchronism withthe signals received on the solid ring M36 from. the line relay 94 so asto connect the segments numbered l to 5 of the segmented ring |61 withthe solid ring during the reception of the variable impulses yl to 5respectively of the signal code combination. As the sixth pulse relay isenergized battery at its make contact is connected through the tongueover conductors |55 and |51, through the makebefore-break contact |60,associated with the tongue |58 of the first receiving transfer relay|2|, over conductors |59 and |6| and through the lower winding of thesecond receiving transfer relay |21 to ground. Battery is also connectedfrom the tongue of the sixth pulse relay ||4 over conductors |55 and|62, through the tongue |63 and break contact of relay |21 and thenceover a conductor |64 through the upper winding of `I 08T compltes itsrevolution, the" circuit 'to the .start'magnet II| will be open and thebrush |08 stopped in its normaly rest position.

:relay |21 to gruunathus neutralizing the effect vof the current in thelower winding so that the itself up by a circuit from battery at thetongue |58 thereof, throughthe lower terminal of contact |60 and thenceoverthe last described circuit through the lower winding of therelay I2|to ground. As the tongue |58 ofthe relay |2| operates to open themake-before-break ContactA |60, battery from the tongue andy makecontact of the sixth pulse relay ||4 is removedfrom the.

lower winding of the transfer relay |21 and replaced by battery fromthetongue |58 of relay |2|. Thus the circuits from segments 1 and 2 of ring|01 tothe' first two coils |29 of relay bank I3I are transferred to thefirst two coils |33 of relay bank |34. Now when the brush |08passes offthe rest segment R, `the-circuit to the sixth pulse relay I|4 and thestart magnet |I| will be opened causing them to return to theirunoperated positions. The start magnet I|| being deenergized allows thelatch'I09 to return to its normal position in the path of the brush |08and will'stopv the samev after the current revolution thereof. Thedeenergization of the sixth pulse relay I4 opensl the seconddescribedcircuit from battery at themake contact thereof through theupper winding of the transfer relay |21, however, the circuit fromthetongue |58 of relay I2| is maintained through the`lower'winding of relayI 21 and this circuit will thereupon cause this relay to operate. Asrelay I 21 operates it remains locked up las longas relay |2I remainsoperated by the above described locking circuit through its' lowerwinding. The locking circuit for relay |2I, with relay |2 1`operated, ismaintained -through al resistance-|68 shunted around the break contactand ltongue |66 of relay |21. Also, as relay |21 operates thevindividual circuits from the third, fourth and fifth l segments of ring|01 tothe third', fourthvand fth coils |29 of the relay bank I3! aretransferred to the third, fourth and fifth coils |33 of the relay bank|34.y 'Ihus' for the described energization and deenergization. ofthesixth pulse relay IM theA individual..circuits'fromfthe five numberedsegments? 1"to 5 of the ring |01 are transferred from respectivecoils-of relaybank 3| to respective coils of relay bankl34, and as thebrush I 08 successivelyy contactsy these' segments the tongues |48 ofthis bank |34 will be operated in accordance with the operation o f thetongue of the line relay 94. As described above, the line relay 94transforms the-'make andbreak signals received from a branch office intopositive 'and negative combinations and applies them to the solid ring|06, and thebrush |08 rotating rin synchronism with these signalsdistributes them to their proper segments. Theftongues |48 of relaybank|34 willv therefore bejsuccessively operated in accordance with the'signal transmitted from the branch office, moving to theirv left handand right hand contacts in responsefto' positive and negative potentialrespectively through their associated coils |33. As the rest impulse 'isa closed line condition, the line V'relayf94 will be' operated to its,markingw'contact"'during the receptionvof this impulse. Now whenthe'brush The manner in which the circuits from th numbered segments ofring |01 are transferred now be vdescribed in connection with the nextreceived lcharacter code group. The start impulse'of the following groupwhich may occur l immediatelyY or after la prolonged lrest period,

causes the release'of the .brush |08 and the energization of the sixthpulse relay ||4 in exactly junction with the preceding group. It shouldbe kept in mind, however, that. the receiving `back to they coils |29 ofrelay bank |3I will y the same manneras previouslydescribedlincontransfer relays I2I and |21 are at this time operated and locked intheir operated positions rby current through their lowerv windings.. Nowas the sixth pulse relay |I4 is operated, battery is f applied throughits make contact and Atongue over conductors |55 and |62, through thetongue |63 andmake stop of relay k|21 and thence over a conductor |69through the upper winding of relay I2I to ground. This circuitneutralizes the circuit in the lower winding and allows the relay I2I toreturn to its unoperated position. As tongue |58 of relayv 2| returns toits unoperated position, it removes battery thereat from thel circuittothe lower windingV of relay |21 andsubstitutes therefor battery from`the make contact and tongue ofthe sixth pulse-relay II4 through theatthis time closed ,make-before-break contact |60. Now-when the sixth"pulse relay I M- is subsequently deenergized, the circuit to thetransfer relay v|21 will be opened, allowing it to return to itsunoperated position. 'Ihus the circuits from the segments of thefring|01 are retransferred back to the associated coils |29 of relayl bank|3| to their original assumed positions and .fromthe above descriptionit is evident that in a cyclefof operation comprising two charactersignal vcodes and two revolutions of therbrush |08, each of the tworelaybanks |3I Aand |34 are in turn connected to the segments ofzring4|01. This sequence of operation continuesuninter'- rup-tedly during theentire period of operation or as long assignals are received on the"line'relay 94' alternately l'storing a signal in on'e relay bankl andthen in the other. f It will be noted that in each complete transferoperation,'the time of the-transfer operation ofthe circuits from thefirst two segments of ring1|01 precedesby a slight amount (i. e., theroperating time of trans-- fer relay.|2'1 and the length rof time relay|'I4 is operated) the 4ktime ofthe transfer operation of the 1 circuitsfrom the Alast three segments. vThe* reason for this slight delay` willbev apparent herea inafter. i 'I'heI manner in which the signals storedon the relay bank 13| 'and' |34 vare transmitted to the' multiplexchannel `willnow be described. 'This operation' isA accomplished by thetwo 'sending'r ing multiplex distributor.

Assume that the first character code combina-- tion from the branch oiceis stored in relay bank |34, as heretofore described, and that for thetime being no other signals are to be received from said office.Therefore, in accordance with the above description the receivingtransfer relays |2| and |21 will be locked up intheir ener.- gzedposition. The relays of relay banks |3| and |34 are polarized and thetongues |36 and |48 thereof respectively remain as positioned by thelast impulse through their respective coils |29 and 33, respectively.Thus the tongues of relay bank E94 will be set in accordance with thesignals from the branch office. The left hand contacts of the tongues|39 and |49 of the relay banks |3i andl |34 respectively are connectedby a conductor |12 to positive potential and the right hand contacts areconnected by a conductor V53 to a tongue |14 of a line battery relayllt. The make and break contactsassociated with the tongue 14 areconnected to positive and nega-- tive potential, respectively. Thesending face plate of the multiplex comprises in addition to the twoabove mentioned main sending rings |52' and |53 two localsending'ring's|11 and 18. The' ringli'l is solid and connected to positive poten.-tial while the'ring |13 is segmented and has two' local segments |19 and|8|. A brush |92 rotating continuously `with the brush |54 wipes overthe multiplex face plate and traverses the local' rings |11 and v|18while brush |54 contacts the' main sending rings |52 and |53.

Let it be further assumed that the sending transfer relays !4| andv |41,the line battery relay |15 and the auto-stop relay |1| are all in theirunoperated or deenergized position and that some' time after the firstcharacter code group is set up on relay bank |34, the multiplex sendingbrush |92l contacts the local segment |19. Thereupon a circuit iscompleted from battery at the solid ring |11, through the brush |82 andsegment |19, over conductors |84 and |36, through themakebefore-breakcontact |81, associated with a tongue |88 of theauto-stop' relay |1|, and thence over a conductor |89 through the upperwinding of relay |1| to ground. This causes the relay |1|V to operatewhich locks itself in an operated po-y sition by batteryfrom the tongue|98 thereof through the lower half of contact |81, over conduotor |89and through the upper winding of the relay. Shortly thereafter the brush|82 contacts local segment |8|, completing a circuit therefrom over aconductor |9| and through the winding of a sixth pulse sending relay |92to ground, causing this relay to momentarily oper-- ate. the makecontactsv of which are connected to battery and as the tongue |94operates, it connects battery over a conductor |95 to a point |91 wherethe current divides, half `continuing from this point over a conductor|98, through the tongue |99 and make contact of relay |1|, which is atthis time' energized, and thence over a conductor 29| through thelowerwinding of relay |19, the other half continuing from point |91 overa conductor 292, through a make-beforebreak contact 293 associated witha tongue 294 of relay |19 and thence 'over a conductor 295 through theupper winding 'of'relay |15. As the upper and lower winding of relay|1|iare opposed to one another, the relay will not operate.

As the tongue |93 of'relay |92 operates, it connects batterytherethrough over a conductor 2.01, through the make contact and tongue298 of relay 1| and over a conductor299 lto a point 2| The relay |92 hastwo tongues |93 and |94,

Here the current divides and causes'the sending transfer relays |4| and|41 to operate and lock themselves in an operated position in exactlythe same manner as the receiving transfer relays |2| and |21 wereoperated and locked in an operated position by animpulse from thereceiving sixth pulse relay ||4 as hereinbefore described and adescription of the detailed operation and locking of these relays |4|and |41 is thought to be superfluous herein.

As the relays |4| and |41 operate, the tongues |48 of the relay bank |34are connected to associated segments of the ring |52 by the circuitshereinbefore described and some time thereafter the main sending brush|54 successively connects these segments to the solid ring |53. f Ihecode signals thereupon are transmitted over conductor |55 and throughthe multiplex line relay 23 to the multiplex circuit I6. Thus the rst.character signal from a branch oilice is transmitted tothe multiplexchannel. i

Now let it be assumed that the second character code signal was receivedby the start-stop receiving distributor and setup lon the relay bank |3|and the brush |09 brought to rest for the time being as hereinbeforedescribed during the transmitting of the first signal by the multiplexsending distributor, or any time before the brush |92 again contactedthe local segment |19. For this condition the receiving transfer relays2| and |21 will be deenergized and as it is assumed that the multiplexbrushes |92v and |83 have completed but one revolution, the auto-stoprelay |1| will still be energized. Therefore, when the brush |82contacts'local segment |19 the second time the conditions of none of therelays change as the circuits from this segment are open. However, asthe brush |82 subsequently contacts local segment |8I, the sixth pulsesending relay |92 is momentarily energized and applies potential to eachof the tongues '|93 and |94 thereof. The line battery vrelay |15' willnot be energized by the movement of the tongue |94 as current will owthrough both of the windings of the relay |15. As the tongue [|93operates, battery is applied therethrough over conductor 201', throughthe make contact and tongue 203 of the auto-stopy relay |1| and overconductors 209 and 2|2 to the tongue 2 I3 of relay |41. This impulsecauses the sending transfer relays |4| and |41 to be returned to theirunoperated positions in exactlythe same manner as the second describedimpulse from the receiving sixth pulse relay 4 caused the receivingtransfer relays |2| and |21V to be returned to their unoperatedpositions, and as the relays |4| and |41 return to normal, the tongues|36 of relay bank |3| are connected by the `described circuits toI the Achannel segments of ring |52. Now when the multiplex ysending brush |54again contacts the A channel segmentsy of ring |52, the character signalstored inrelayfbank |3| will be transmitted to the multiplexy circuit.This sequence of transfer operations of the sending and receivingtransfer relays |4| and |41,- and |2| andl |21 would continueindefinitely, alternately 'transmitting from one relay bank while theother was in the process of being set up, if the signal groups werereceived` at a uniform rate and the multiplex brushes rotated inVsynclironism therewith. This condition would give a very satisfactoryover-lap, i. e., `the angular lead of the brush |98 of the receivingstart-stop distributor with respect to thebrushes |82 and |54 of themultiplex sending distributor. However, thisl is not the suchy a*conditionc'urr'ent vWm then newY from the case asthe start-stop signalgroupsy are' received at a non-uniform rate and the multiplexbrushesrotate continuously at a speed slightly in e'xcess of the possiblemaximum speed of transmission of the start-stop equipment. Therefore,when the start-stop signals are received at the normal rate and up tothe maximum rate theover-la'p is gradually reduced until bothdistributors" are connected to 4the same relay bank, .|3| or |34, duringa large part of the time. During' this condition the start-stopreceiving brush'` |08 might be in the course of setting up a signal inthe fifth coil of a relay bank such as |3| While the multiplex brush |54was transmitting an impulse representative of the setting of the thirdtongue of the same relay bank. Obviously, a closer approach than this ofthe sending brush I 54 to the receiving brush |08 or the decrease of theover'- lap to thisextent would be disastrous since an attempt wouldeventually be made tov send a pulse from a tongue ofr a relay bank whichhadnot yet operated or had time to settle on 'its contact.

Therefore, when the overlap decreases to a predetermined minimum, aconditionis set upv which automatically restores the overlap to'amaximum. 'I'his is accomplished by preventing the sending transferrelays |4| and |41 from performing their normal transfer operation onthe following revolution of the multiplex brush while the receivingdistributor proceeds to set up the next character signal on the otherrelay bank. During this revolution of the multiplex brushes an allspacing signal is sent to the A channel of the multiplex from the relaybank from4` which the previous signal had been transmitted. On thesucceeding revolution of the multiplex brushes following thetransmission of the al1 spacing signal, thesending transfer relays |4|and |41 operate and connect the multiplex segments with the relay bankand transmit the signal therein which wasl set up by the start-stopreceiving distributor during the transmission of the all spacing signalby the multiplex, thereceiving distributor at the time setting up asignal in the other relay bank. Thus the overlap'is restored to amaximum and transmissionproceeds in a normal manner until the brushes ofthe multiplex sending distributor `have again nearly caught up withthose Yof the start-stop ref ceiving distributor, or reduced the overlapto the.' minimum at which time the process is repeated.v of therepeater: one

VDuring' normal operation relay bank such as |3| is being set up whiletransmission is taking place from'the other: |34, 'l or vice versa.Therefore, while the sending.' transfer relays |4| and |41 are operatedandl unoperated the receiving transfer relays |2 Ifand |21 will normallybe unoperated and operated respectively. `Also, as pointed out abovelthe auto-stop relay |1| is normally maintained locked in its energizedposition andthe line `battery normally maintained in its deenergizedposition, the operation ofthe sending ysixth pulse relay on subsequentrevolutions making no change in their conditions as long as the, overlapbetween the reception and transmission remains adequate.

Assume now that the position of the multiplex I withrespect to thesending brushesy 82 and |54 |08 changes to slower start-stop'receivingbrush Isuch an extent that while `the multiplexk local` brush |82 is incontact with local segment"|19,

the tongue of the sending and receiving transfer relays |4| and |41, and|2| and .121 respectivelyare in the same corresponding positions.During:

segment `|19, over conductors |84 and y2||i, through a'tongue 2|1 andmakexor break contact of relay |4|, over one of the conductors 2| 8 or2|9,Y respectively, through the make or break contact,respectively, andtonguel22| of relay 2| and *thence over a conductor 222 through the`lower winding of 'the auto-stop relay |1| to ground. Y As statedabove,this relay |1| is normally energized by a locking circuit through itsupper winding and thereforethis circuit through the lower winding willneutralize the eld created by the locking Winding allowing the relayarmatures to disengage their respective contacts. As

- the brush |82 subsequently contacts the segment |8| and causes vtheenergization of the sixth pulse relay |92, vbattery from thetongue |93thereof will not cause a change in the 'condition of the sendingtransfer relays |4| and |41'asthe circuit thereto is open at the tongue208-and make contact of the at this time deenergized auto-stop relay|1|." However, `battery will flow from the make contact and tongue |94of relay |92 over conductorsv|96 andv 202 through the make-before-breakContact 293 and thence overconductor 206 andthrough the upper .windingof the line battery relay "|16 to ground; Asv the circuit from the sametongue,v |94 of relay |92 to the lower Winding of relay |16 is open atthe tongue |99 ofrelay |1|, the current in the upper wind'- ing of relay|16 causes it to operate. This relay |16 is thereupon locked in itsenergized position by battery from itstongue 204, through the lower' themultiplex segments. The relay bank will bey the same 'one from whichthelast Ipermutation co'designal was sent `as the condition of Vthesending transfer relays 4| and |41 have not changed. f Since theyreceiving transfer circuit has'not been interrupted, 'the receivingtransferl relays |2| and |21 will havev inthe lmeantime been moved' togacondition opposite to that'of the sending transfer relays'l4l and |41;Therefore, as local multiplex brush |82 contacts local segment |19following the 'transmission' of ythe vall spacing signal a circuit" willbe completed fromthis segment over conductorsllland |86, through themake-beforei-br'eak Contact |81 and `thence over conductor |89 andthrough the rupper winding of the auto-stoprelay |1| "to ground, causingthis relay to become energized and lock itself as hereinbeforedescribed'. The 'circuit from the seg ment |19 to the lower" windingofrelay |1| will be i open at the tongue 22|'of relay |2|. Now as themultiplex brushy |82 contacts segment |81 to cause the operation of thesixth pulse sending relay |92, battery is connected' to the tongue-|94thereof, over conductors |96" and'4 98 through the tongue |99 and make'contact'of vrelay`|1| and over oonductor`20| 'through' the lower windingof relay |16 to ground. This circuit neutralizes the effect of thelocking circuit in the upper winding and the relay thereupon returnstonormal. At the Sametime an operating impulse for the sending transferrelays |4| and'l41fis supplied esok g main ofce.

thereto from the tongue |93 of relay i532 `to operate the same in themanner described and operation from this point proceeds in the normalmanner until the overlap is again reduced to the minimum, whereupon theabove described functions are repeated.

The above paragraphs cover the operation of the repeater on a singlebasis, i. e., the transmission to and from the branch oiiice such as Aor C over a single tie line. In order to send to and receive from abranch ofce such as A or C on a duplex basis, i. e., the transmission toand from a branch office over separate tie lines, the tongues of theswitch 51 are moved to their lower stops. This operation, as is obvious,disconnects the conductor 58 from conductor 54 and by means of a tongue22@ of the switch 5l' connects a conductor 224 to conductor 54. Theconductor 2M is' connected through a jack 222i to a branch oiiicereceiving tie line such as 221. As described the signals received overthe multiplex channel pass over the conductor 54 and therefore theoperation of the switch extends these signals to the branch oice by Wayof the branch office receiving tie line 221'. The operation of theswitch 5'! as is obvious, also disconnects the line relay 94 from inseries with the sending solid ring 69 of the start-stop sendingdistributor 68 and negative battery at the reversing switch 4,9 so thatthe signals from the branch office over a tie line II pass only throughthe line relay. Thus a branch oflice may be adapted to operate on aduplex basis.

If one section ofthe complete system such as the multiplex channel I'I,should happen to fail, it would ordinarily render the whole systeminoperative. At such a time, by operating the switch 51 of theassociated repeater, such as 2| to its lower stops, the failed sectionof thesystem is isolated and operation may be continued over the rest ofthe system, such as between branch ofce stations A and B. The circuitsfor such operations are obvious from the above description.

The polarity of spacing and marking impulses on adjacent channels of amultiplex circuit are for obvious reasons sometimes reversed.'Therefore, the polarized relays 3Ia to 3Ie will be oppositely operatedwhen associated with different channels. To take care of this conditionthe switch 3B is provided and if the circuits therethrough are traced,it will be apparent that its` operation provides for the reversedpolarity of the multiplex signals.

It will be noted in tracing the circuit from the branch oice A that itis connected to battery at the reversing switch 49 of its associatedrepeater. At a main oice such as Y which is associated with a branchoiiic'e B by means of two tie lines I3 and I4, the switches 49 at therepeaters I9 and ZI must be thrown in opposite directions. The reasonfor this is that one end of the tie lines I3 and I4 must be grounded andby scrutinizing the circuits it can readily be seen that the operationof the reversing switch 4t merely reverses ground and battery on some ofthe circuits.

At times it may be desirable for the branch oice operator at a stationsuch as A to attract the attention of an attendant atthe associated Toaccomplish this the branch oiiice operator opens the branch oiiice tieline II by an approved method such as removing the printer plug from itassociated jack for a few seconds and then again inserting it. Thisabnormal opening of the line circuit I I allows the normally energizedslow-to-release relay 53 to become deenergized. The relay G3 is normallyenergized and is adjusted so that open line conditions of ordinarysignals do not cause it to release. When the relay 63 is released asdescribed above, the two tongues 60 and 52 thereof make contact withtheir associated break contacts. The tongue t2 shorts out the relay coilwhile the tongue E!) completes a circuit to a signal lamp 55. When theline circuit is again closed by replacing the plug the relay 63 remainsdeenergized until the attendant thereat operates the key GII to open theshunt circuit through the tongue 62.

Jacks 59 and 22B are provided at each repeater so as to permit theattendants thereat to plug in a printer for monitoring purposes or so asto be able to communicate with any other station on the system.

It is obvious, of course, that various changes and modifications of thecircuits` shown and described herein may be made without departing fromthe spirit or essential attributes of the invention, and it is desired,therefore, that only such limitations shall be placed thereon as areimposed by the prior art or are specifically set forth in the appendedclaims.

What is claimed is:

l. In a telegraph system, a station, a plurality of multiplex circuitsterminating at said station, start-stop recording means at said station,means for transferring marking and spacing signal conditions receivedover one of said multiplex circuits through said start-stop recordingmeans and into another of said multiplex circuits, and means forrecording said signal conditions on said start-stop recording means atsaid station.

2. In a telegraph system comprising a plurality of multiplex operatedcircuits, a plurality of simplex operated circuits, said simplexoperated circuits being greater in number thanl said multiplex operatedcircuits, means for alternately connecting said simplex operated' andsaid multiplex operated circuits in a continuous circuit; means fororiginating simplex signals at each of said simplex operated circuitsand means for recording signals originating at any one of said' simplexoperated circuits at all of said simplex operated circuits.

3. In'a telegraph system, a circuit comprising a plurality of multiplexoperated sections and a plurality of vsimplex operated sections,transmitting and receiving means in each of said simplex operatedsections and means comprising said multiplex operated sections forrecording signals originating at the transmitting means in any one ofsaid simplex operated sectionsV on the receiving means in each of saidsimplex operated sections.

4. In a telegraph-circuit comprising a plurality of multiplex operatedsections separated by simplex operated sections, recording means in eachof said simplex operated sections, means for extending signals from amultiplex operated section through a simplex operated section and therecording means thereat to operate the same in accordance therewith andmeans for further extending said signals into another of said multiplexoperated sections.

5. In a telegraph circuit comprising a plurality of multiplex operatedsections separated by simplex operated sections, means for extendingtelegraph signals from one. multiplex operated section through a simplexoperated section and into other multiplex operated sections, recordingmeans in each of: said simplex operated sectionsv and means forrecording said signals on-said recording means in each of said simplexoperated sections.

6. In a. telegraph circuit comprising a plurality of series multiplexcircuits adapted to operate at substantially the same speed, simplexoperated transmitting and receiving mechanisms at the ends of saidcircuit and at the junction points of said multiplex circuits adapted toreceive signals at a faster rate than the operating speed of saidmultiplex circuits and to transmit signals at a slower rate thantheloperating speed of said multiplex circuits, meansffor-transmittingsignals iro-mwany one of said'sii'nplex transmitting mechanisms at atime and means for recording said signals on each of saidsimplexoperated receiving mechanisms, 'l

' KARL B. DUERR.

